2 package Moose::Util::TypeConstraints;
8 use Scalar::Util 'blessed';
10 our $VERSION = '0.03';
12 use Moose::Meta::TypeConstraint;
13 use Moose::Meta::TypeCoercion;
17 my $pkg = shift || caller();
18 return if $pkg eq '-no-export';
20 foreach my $export (qw(type subtype as where message coerce from via find_type_constraint)) {
21 *{"${pkg}::${export}"} = \&{"${export}"};
27 sub find_type_constraint { $TYPES{$_[0]}->[1] }
29 sub _create_type_constraint {
30 my ($name, $parent, $check, $message) = @_;
31 my $pkg_defined_in = scalar(caller(1));
32 ($TYPES{$name}->[0] eq $pkg_defined_in)
33 || confess "The type constraint '$name' has already been created"
34 if defined $name && exists $TYPES{$name};
35 $parent = find_type_constraint($parent) if defined $parent;
36 my $constraint = Moose::Meta::TypeConstraint->new(
37 name => $name || '__ANON__',
42 $TYPES{$name} = [ $pkg_defined_in, $constraint ] if defined $name;
46 sub _install_type_coercions {
47 my ($type_name, $coercion_map) = @_;
48 my $type = find_type_constraint($type_name);
49 (!$type->has_coercion)
50 || confess "The type coercion for '$type_name' has already been registered";
51 my $type_coercion = Moose::Meta::TypeCoercion->new(
52 type_coercion_map => $coercion_map,
53 type_constraint => $type
55 $type->coercion($type_coercion);
58 sub export_type_contstraints_as_functions {
61 foreach my $constraint (keys %TYPES) {
62 *{"${pkg}::${constraint}"} = find_type_constraint($constraint)->_compiled_type_constraint;
70 my ($name, $check) = @_;
71 _create_type_constraint($name, undef, $check);
75 unshift @_ => undef if scalar @_ <= 2;
76 _create_type_constraint(@_);
80 my ($type_name, @coercion_map) = @_;
81 _install_type_coercions($type_name, \@coercion_map);
85 sub from ($) { $_[0] }
86 sub where (&) { $_[0] }
88 sub message (&) { $_[0] }
90 # define some basic types
92 type 'Any' => where { 1 };
94 subtype 'Value' => as 'Any' => where { !ref($_) };
95 subtype 'Ref' => as 'Any' => where { ref($_) };
97 subtype 'Int' => as 'Value' => where { Scalar::Util::looks_like_number($_) };
98 subtype 'Str' => as 'Value' => where { !Scalar::Util::looks_like_number($_) };
100 subtype 'ScalarRef' => as 'Ref' => where { ref($_) eq 'SCALAR' };
101 subtype 'ArrayRef' => as 'Ref' => where { ref($_) eq 'ARRAY' };
102 subtype 'HashRef' => as 'Ref' => where { ref($_) eq 'HASH' };
103 subtype 'CodeRef' => as 'Ref' => where { ref($_) eq 'CODE' };
104 subtype 'RegexpRef' => as 'Ref' => where { ref($_) eq 'Regexp' };
107 # blessed(qr/.../) returns true,.. how odd
108 subtype 'Object' => as 'Ref' => where { blessed($_) && blessed($_) ne 'Regexp' };
118 Moose::Util::TypeConstraints - Type constraint system for Moose
122 use Moose::Util::TypeConstraints;
124 type Num => where { Scalar::Util::looks_like_number($_) };
130 subtype NaturalLessThanTen
132 => where { $_ < 10 };
140 This module provides Moose with the ability to create type contraints
141 to be are used in both attribute definitions and for method argument
144 =head2 Important Caveat
146 This is B<NOT> a type system for Perl 5. These are type constraints,
147 and they are not used by Moose unless you tell it to. No type
148 inference is performed, expression are not typed, etc. etc. etc.
150 This is simply a means of creating small constraint functions which
151 can be used to simplify your own type-checking code.
153 =head2 Default Type Constraints
155 This module also provides a simple hierarchy for Perl 5 types, this
156 could probably use some work, but it works for me at the moment.
170 Suggestions for improvement are welcome.
174 =head2 Type Constraint Registry
178 =item B<find_type_constraint ($type_name)>
180 This function can be used to locate a specific type constraint
181 meta-object. What you do with it from there is up to you :)
183 =item B<export_type_contstraints_as_functions>
185 This will export all the current type constraints as functions
186 into the caller's namespace. Right now, this is mostly used for
187 testing, but it might prove useful to others.
191 =head2 Type Constraint Constructors
193 The following functions are used to create type constraints.
194 They will then register the type constraints in a global store
195 where Moose can get to them if it needs to.
197 See the L<SYNOPOSIS> for an example of how to use these.
201 =item B<type ($name, $where_clause)>
203 This creates a base type, which has no parent.
205 =item B<subtype ($name, $parent, $where_clause)>
207 This creates a named subtype.
209 =item B<subtype ($parent, $where_clause)>
211 This creates an unnamed subtype and will return the type
212 constraint meta-object, which will be an instance of
213 L<Moose::Meta::TypeConstraint>.
217 This is just sugar for the type constraint construction syntax.
221 This is just sugar for the type constraint construction syntax.
225 This is just sugar for the type constraint construction syntax.
229 =head2 Type Coercion Constructors
231 Type constraints can also contain type coercions as well. In most
232 cases Moose will run the type-coercion code first, followed by the
233 type constraint check. This feature should be used carefully as it
234 is very powerful and could easily take off a limb if you are not
237 See the L<SYNOPOSIS> for an example of how to use these.
245 This is just sugar for the type coercion construction syntax.
249 This is just sugar for the type coercion construction syntax.
255 All complex software has bugs lurking in it, and this module is no
256 exception. If you find a bug please either email me, or add the bug
261 Stevan Little E<lt>stevan@iinteractive.comE<gt>
263 =head1 COPYRIGHT AND LICENSE
265 Copyright 2006 by Infinity Interactive, Inc.
267 L<http://www.iinteractive.com>
269 This library is free software; you can redistribute it and/or modify
270 it under the same terms as Perl itself.